First she will she have to demonstrate her suitability for managing European science - an area in which she has had little previous involvement during a lengthy political career.
Then she may also have to account for her brief association with Declan Ganley, the Irish businessman who led the campaign for a No vote when Ireland voted against the Lisbon Treaty in June 2008, and again this October when the Irish electorate voted in favour of the EU’s new constitution.
Geoghegan-Quinn was formerly a board member of the Ganley Group, a private equity firm established by Ganley, who is also founder of the eurosceptic political party Libertas. There is no suggestion Geoghegan-Quinn shares his political views. She severed her business links with Ganley long before his emergence as the would-be destroyer of the Lisbon Treaty and long before her nomination as Ireland’s next EU commissioner.
The connection is more of an embarrassment than any real obstacle to her confirmation. Nevertheless, some members of the parliament, which is always anxious to flex its political muscles, will doubtless seek to make her squirm at least.
Although her transition team is by no means taking the confirmation process for granted, it would be surprising if MEPs rejected her nomination. Geoghegan-Quinn was unavailable for comment on her plans for the portfolio in advance of the confirmation hearings.
For the last decade, Geoghegan-Quinn has been a member of the European Union’s public spending watchdog, the Luxembourg-based European Court of Auditors, a position that has kept her out of the spotlight in Ireland. Once a high-ranking cabinet minister, her national profile had sunk so low that a year ago an Irish Sunday newspaper ran a short biographical sketch under the headline: 'Where are they now?'.
That she is back on the political frontline now owes as much to domestic political considerations as it does to her longstanding reputation as a heavy hitter - in Irish politics at least. Ireland's Fianna-Fail-led coalition government recently introduced harsh and unpopular public spending reforms, and is operating on a wafer-thin majority. Upsetting the parliamentary arithmetic by sending a current member of the government to Brussels was therefore never on the cards.
And Brian Cowen, Ireland's Taoiseach (prime minister) - a famously tribal politician - was never likely to offer the post to a candidate from outside Fianna Fail either, even though media speculation had focused on former European Parliament president Pat Cox.
Nominating a woman, Cowen argued, would improve Ireland's chances of landing a substantial portfolio, following a call by Barroso for greater gender balance in the commission.
Geoghegan-Quinn's long exile from frontline Irish politics arguably strengthens her position. She is untainted by the domestic policy failures that left Ireland's property-fuelled economy particularly vulnerable to the global economic recession.
Even more importantly, her decade at the European Court of Auditors has given her an intimate knowledge of the workings of the EU's institutions and the allocation of its annual budget, which will reach almost €123 billion next year. And although her most recent area of focus was international aid, it will also have given her some direct insight into the workings of DG Research, the department of the Commission responsible for most R&D spending in Brussels.
Last July, for example, the Court of Auditors released a report that was critical of aspects of Framework Programme 6, including its lack of an “explicit intervention logic” linking the newly introduced FP6 project structures or instruments, Networks of Excellence and Integrated Projects, to clearly defined, realistic objectives.
As a result, these new instruments were judged to have only partially realised their objectives, the report concluded. The Networks of Excellence “often did not achieve a progressive and self-sustainable integration of the research activities between the network partners,” while the Integrated Projects often failed to attract additional funding from non-EC sources.
The big question now is whether Georghegan-Quinn will be able to make her mark in a complex and increasingly important area that is, for the most part, alien territory. Her immediate predecessor, Janez Potočnik, evinced a low-key, managerial style but accomplished a lot during his term, including a significant expansion of the EC's science budget, the establishment of the European Research Council and the initiation of Joint Technology Initiatives in six key areas, with the goal of embedding industry more deeply into Commission-funded research.
His predecessor, Philippe Busquin, can claim much of the credit for the creation of the European Research Area, the grand idea that encapsulates the notion of an integrated, pan-European research effort.
Potočnik was an academic economist before he entered politics. Busquin was a physicist.
According to an Irish government source, Geoghegan-Quinn's specific knowledge of the research field is not the issue. “What you look for is political skills, common sense, presentation skills and the ability to lead a team which contains the expertise she needs to do the job,” he said.
Presuming Geoghegan-Quinn survives the parliamentary confirmation hearings, she will have ample opportunity for bringing those skills to bear on a portfolio that is increasingly regarded as being key to improving Europe’s faltering economic competitiveness.
See the Commission website for Geoghegan-Quinn's official CV.